HTC Vive Lighthouse 1.0 Laser Diode Replacement With One From a CD Burner

If your HTC Vive Base Station 1.0 is blinking red, the first thing to try is unplugging it and plugging it back in, then reinstalling Steam VR and if that doesn't help, rolling back the firmware on the base station can resolve the problem. For me this did get rid of the blinking light, but the base station was not doing any tracking.

At this point you should check the base station using the camera of your phone, there should be the array of 9 purple looking IR LEDs and on two sides of that there should be two more a little bit line-shaped lights, which are the lasers that do the x and y sweeping of the room. In the picture the one on the top is working normally and the one on the bottom does not have one of the lasers showing. It is possible that this is just caused by a mirror that has fallen out of it's place (you can check by shaking the lighthouse and listening for a rattle) or maybe even a loose connection. For me the problem was a burnt out laser diode though and so this guide will walk you through doing a practically free repair.

Supplies

Old, preferably free CD burner (make sure burns CDs, not just a DVD burner with CD reading)
Some screwdrivers and pliers
A vice is handy
Soldering iron
Hot glue
Hairdryer (helps with taking apart)
Plastic prying tool (credit card, guitar pick)
Disposable gloves to avoid finger prints on stuff

Step 1: Opening Up and Maybe Just Replace the Whole Module

The first step is to disassemble the device, and if you can find a complete replacement laser diode module for the lighthouse, all you need to do is follow this very helpful video guide for how to open up the base station and replace the module:

https://www.youtube.com/watch?v=LnjjVqgSDRM

Basically to get out the laser diode module you have to pry off the front translucent plastic, heating it up with a hairdryer makes the glue soften and you should use a plastic guitar pick or a credit card or something for the prying to not damage the plastic. Then just remove a couple of screws that keep the insides of the lighthouse in the case. Last step is to remove the glue holding the laser module in place and pulling it out with pliers. Also disconnect the cable.

The laser diode is on the opposite side of the assembly as to light you are seeing when the unit is powered. After opening up the module it is also a good idea to check that both of the lenses are attached to the spinning wheels, if not, you should find the lens somewhere inside the case and glue it back in place with superglue or epoxy and retest the lighthouse.

You can get a complete module from here:

https://www.vr-part.com/product/htc-vive-base-station-laser-diodes

Or if you can find a broken lighthouse listed somewhere for cheap, you could salvage a module from that.

If you cannot find a replacement module or like me don't want to pay 60$ + shipping for it like me, you can actually replace the laser diode itself with one from a CD burner, which you might have laying around already or could get for very cheap if not free. According to the internet, the laser diodes inside of a base station are 830nm laser diodes and the laser diodes inside a CD burner are 780nm. The power level of the CD burner lasers should be higher, but because the lighthouse has to have a constant current driver for the lasers, this should be fine.

You can also buy laser diodes for maybe around 15 dollars, at least I've seen 808nm diodes being sold on amazon, which should be fine.

Step 2: Finding a Suitable Optical Drive

The first thing the sacrificial optical drive has to have is the capability to burn CDs and this is not necessarily the case even if the thing can burn DVDs or BluRays so you have to make sure it specifically has the ability to burn CDs. Next you need to open up the drive and disassemble it to the point where you can see the carriage on the rails. Now you should look closely at the laser module, if your drive is a DVD / CD burner drive like mine is, it should have two of those 3 legged laser diodes marked with the red circles. Some CD burners have a different type of laser(s), I took apart two drives because the first one wasn't suitable. Once you find a suitable optical drive, take out the carriage and desolder the flexible PCB off of both of the laser diodes. Take notes of which pins are actually connected here, it might help you with connecting the laser diodes later.

Step 3: Find Out Which Laser Diode Is the IR One

At this point I have to warn you about the danger of lasers. The laser inside of the lighthouse is supposed to be safe to even look at (although I wouldn't look at it with your naked eyes without the front cover), but the laser inside the CD burner is not (at least if you provide it with more power than the lighthouse does), also the lasers we are dealing with here are IR so you cannot see them with your eyes.

YOU HAVE TO HAVE A PAIR OF LASER GOGGLES THAT SPECIFICALLY CAN PROTECT YOU FROM 780nm IR LIGHT TO PROCEED!

I definitely do not recommend this, but what I did was that I just looked at the lasers through the camera of my phone.

Also a warning about measuring laser diodes with a multimeter: I managed to break one with an auto ranging multimeters resistance measurement, not sure how but be warned.

So there are the two separate laser diodes, one of them is a red laser for the DVD and the other one is the IR laser for the CD burner. Now you should solder two wires to one of the diodes according to one of the pinouts in the pictures (these seem to be the most common pinouts for these small laser diodes, mine was the one that has the negative in the center pin), you can use the notes you took in the last step to figure out which pinout is the correct one for you as there should be one pin not connected.

Now test it with a coin cell battery or with a 5 volt source through a 50-150 ohm resistor (maybe start with 150 and go down from there to be safe) or the best case would be to use a current limited power supply set to 20mA to start and going up from there (not over 100mA). If your laser starts emitting red light like in the picture, it's the DVD one and you should test the other laser diode. Once you find the one that emits light that you can see through your phone camera as a similar color to the ones in the base station but you cannot see it with your eyes, you know it's the right one.

Step 4: Get the Laser Diode Out of the Carriage

The only way I could figure out for doing this was to use a hacksaw and do it very carefully and a little at a time. From what I understand, the laser diodes are press fit into the housing and this seems to be the only way to get them out intact. Once you've gotten it out, you should now have a plain 3-pin laser diode. You also should have disassembled the base station according to the video in the first step and taken out the laser diode module from it.

Step 5: Disassemble the Laser Module

This step may seem a bit violent but it worked fine for me, you should just be careful with the lens inside the module.

Pry off the black epoxy and the wires off of the module and cover the lens side with some tape.
Put the module in a vise (be gentle to not squeeze the module too much, the lens is fragile).
Very carefully drill a small hole through the laser module (but make sure not to go too much deeper than the length of a laser module (you can measure with the new one) as to not break the lens.
Get a screw big enough that it can self tap into the hole and screw it inside of the old laser diode.
Pull the laser diode out of the housing with the screw using pliers.

At this point you have the laser diode out of the housing, but there may be a black spacer ring still around it. If you also have this, you should put the black housing with the laser inside it into the vise again and pull from the screw to get the parts separated.

Step 6: Reassemble the Laser Module

First press the new laser diode into the black spacer ring and then the assembly into the laser module housing. I used pliers and the vice for this, be careful not to bend the pins of the laser diode too much.

Now you have to solder the wires into the new laser diode. The red one is the positive and the black one is the negative, you should again refer to the notes you took when testing the laser diode. I left the white one disconnected.

At this point it may be a good idea to test the laser diode by connecting the wire to the lighthouse and checking through your camera to make sure there is light coming out of the laser (and that it is of similar color to the other laser). Note that the lasers turn off when you move the unit, so you should set it on a table or something.

Step 7: Reassembly and Firmware

Reassembling is showed nicely in the video linked in the first step. Basically put the module back in its place and glue it in with hot glue, then screw the unit back into the housing and place the front back on there.

One of the lasers should now be a little brighter than the other one (you might also be able to see it with your naked eye a little better even through the front filter), I'm not sure if looking at the new laser is bad for your eyes long term, so I would suggest not looking at it directly too much, but the lighthouse should still be limiting the power to a similar level as with the original laser. I actually broke the other laser in the lighthouse with my multimeter somehow so in the picture both lasers look the same (since both are 780nm CD-burner lasers) but they are a little brighter compared to the other unit.

If you are on the new firmware version, the lighthouse should not work and it should be blinking red, so you have to downgrade the firmware and remember not to upgrade it ever again.

I did this fix 10 months ago now and the base station has been working fine ever since!

Introduction: HTC Vive Lighthouse 1.0 Laser Diode Replacement With One From a CD Burner